Hi Daniel!
Actually the runway required for take-off by any transport aeroplane actually depends on many factors; first is the mass (airframe+fuel+passengers+luggage). Then comes runway elevation (its height above mean sea level), runway slope (going up or down-hill), wind direction and velocity, air pressure and air temperature.
To answer your original question: any source that states that such-and-such aeroplane needs so-and-so runway for takeoff, without specifying the circumstances, is not to be believed. While I'm not A330 pilot, I'm pretty certain that the empty A330 with fuel for only couple of circuits will be happy with less than 2000m runway at sea level. However, fully loaded with passengers and fuel for six hours flight, it might need more than 3000m. And I've personally seen one A330 taking 210 passangers on three hour flight, from 2500m runway without problems.
Hope this helps.
C.